Pump Device

ABSTRACT

A pump device includes a pulsator as a drive element for a main pump head which is situated in a delivery line and the working chamber of which is provided with a suction-side non-return valve and a pressure-side non-return valve. The working chamber of the pulsator is connected via an oscillation line, which is filled with delivery medium, to the working chamber of the main pump head in such a way that the pulsator sucks delivery medium out of the delivery line and into the working chamber of the main pump head, or presses delivery medium out of the working chamber, in an oscillating fashion. A ventilation valve is provided for ventilating the working chamber of the pulsator, and the ventilation line is a time-controlled valve and/or a pressure-controlled double-seat valve. A device may be provided for introducing a liquid into the working chamber of the pulsator and/or the oscillation line.

The invention relates to a pump device having a pulsator as a driveelement for a main pump head which is located in a delivery line and theworking chamber thereof is provided with a suction-side non-return valveand a pressure-side non-return valve, as claimed in the preamble ofclaim 1.

Within the meaning of the present disclosure of the invention, a“diaphragm pulsator” is understood in that it corresponds to a pistondiaphragm pump which does not necessarily have suction-side andpressure-side non-return valves, but instead generally has all thefeatures of a piston diaphragm pump. The person skilled in the artunderstands by “piston diaphragm pump” a piston pump coupled to adiaphragm, the displacement of the piston being transmitted via ahydraulic coupling to the diaphragm. In the same manner as pistondiaphragm pumps, diaphragm pulsators may also comprise, in particular, apreferably position-controlled diaphragm refill device and/orventilating device for the hydraulic fluid, as is disclosed, forexample, in EP 0 085 725 A1.

In particular, the invention relates to a pump device having a pulsator,in particular a diaphragm pulsator, as a drive element for a main pumphead which is located in a delivery line and the working chamber thereofis provided with a suction-side non-return valve and a pressure-sidenon-return valve. The working chamber of the pulsator is directlyconnected, via a transfer line filled with fluid to be delivered, to theworking chamber of the main pump head such that the pulsator sucks fluidto be delivered in an oscillating manner from the delivery line into theworking chamber of the main pump head or forces said fluid to bedelivered out of the working chamber. The pump device according to theinvention is particularly well-suited for delivering suspensions, suchas for example mixtures of biomass and supercritical water and, inparticular, for high pressures and temperatures.

Pumps of this type are disclosed in EP 0919724 B1 and EP 1898093 A1. Inthis connection, a main pump head located in the delivery line is drivenby a further pump head which is denoted as a pulsator. Such a pumpdevice is also denoted as a “remote head” pump. Such pump devices aretypically used for pumping fluids with a high proportion of solids andat high temperatures. The known pumps may not be easily used, however,with particularly aggressive media for delivery, such as for examplesupercritical aqueous solutions, in particular where processes arepresent with a very high throughput at high temperatures and highpressures.

The object of the invention is to provide a pump device of theaforementioned type which may be used for pumping aggressive media fordelivery at a high temperature and which nevertheless operates with ahigh degree of reliability at low cost, which is why in particular thecontamination of the pulsator by solid particles should be avoided.

This object is achieved by a pump device according to the features of atleast one of the independent claims. Advantageous embodiments of theinvention are provided in the dependent claims.

According to an embodiment of the invention, a pump device is providedhaving a pulsator as a drive element for a main pump head which islocated in a delivery line and the working chamber thereof is providedwith a suction-side non-return valve and a pressure-side non-returnvalve, the working chamber of the pulsator being connected, via atransfer line filled with fluid to be delivered, to the working chamberof the main pump head, such that the pulsator sucks fluid to bedelivered in an oscillating manner from the delivery line into theworking chamber of the main pump head or forces said fluid to bedelivered out of the working chamber, a venting valve being provided forventilating the working chamber of the pulsator, the venting valve beinga time-controlled valve and/or a pressure-controlled double-seat valveand/or a device being provided for introducing a fluid into the workingchamber of the pulsator and/or the transfer line.

The use of a time-controlled valve and/or a pressure-controlleddouble-seat valve has the advantage that the time in which the valve isopen for ventilation is able to be kept very short, whereby undesirablesecondary flows may be avoided which could result in increasedcontamination of the pulsator by solid particles.

The introduction of fluid into the working chamber of the pulsatorand/or the refilling of fluid to be delivered into the working chamberfor compensating for losses, for example as a result of ventilating theworking chamber, has the advantage that fluid does not have to becompensated by the driven main pump head, and thus no solid particlesare transported from the main pump head to the pulsator.

According to the invention, the fluid may be water and/or fluid to bedelivered and/or another suitable fluid.

According to the invention, the time-controlled and/orpressure-controlled venting valve may be a single-seat valve and/or adouble-seat valve.

According to the invention, the device for introducing a fluid into theworking chamber of the pulsator and/or the transfer line may comprise atime-controlled and/or pressure-controlled refill valve and/or a refillreservoir.

According to the invention, the time-controlled and/orpressure-controlled refill valve and/or venting valve may betime-controlled and/or pressure-controlled so that after a start-upphase of the process the refill valve and/or venting valve is closedand/or the upper limit value for closing the time-controlled and/orpressure-controlled refill valve and/or venting valve is increased aftera start-up phase of the process and/or after a start-up phase of theprocess the lower limit value is reduced for closing the time-controlledand/or pressure-controlled refill valve and/or venting valve.

Preferably, the pressure to which the refill reservoir is subjectedsubstantially corresponds to the pressure in the working chamber of thepulsator.

According to an embodiment of the invention, the refill valve may be atime-controlled and/or pressure-controlled valve between the workingchamber and the refill reservoir.

According to the invention, the working chamber of the pulsator may beconnected via the and/or a further venting valve to the suction side ofthe delivery line.

According to the invention, therefore, the suction side of the deliveryline may advantageously be arranged above the venting valve forautomatic ventilation.

Alternatively or additionally, according to the invention the workingchamber of the pulsator may be connected via the and/or a furtherventing valve to the pressure side of the delivery line.

According to the invention, the venting valve may be force-controlled incombination with a return pump, in particular in a time-controlledmanner.

Alternatively or additionally, according to the invention the workingchamber of the pulsator may be connected via the and/or a furtherventing valve to a refill reservoir for compensating for leakage lossesin the working chamber of the pulsator and/or the transfer line.

Alternatively or additionally, according to the invention the workingchamber of the pulsator may be connected via the and/or a furtherventing valve to a collection container for collecting and possiblysubsequently returning fluid to be delivered which is produced duringthe ventilation.

According to the invention, the valve may be time-controlled and/orpressure-controlled such that it is closed at least above a specificpressure.

The pulsator produces in the working chamber a continuously alternatingpressure at a compression phase and a suction phase. In order to preventa weakening of the flow from the transfer line for driving out possiblysucked-in solid particles, ventilation should not be carried out atleast above a specific pressure in the working chamber in order toprevent a drop in pressure in the working chamber, even though this maybe small, and thus a reduction in the flow from the transfer line.

According to the invention, the valve may be time-controlled and/orpressure-controlled such that it is closed at least below a specificpressure.

Alternatively or additionally, ventilation should be avoided below aspecific pressure in the working chamber of the pulsator, as due to thedrop in pressure, even though this may be small, greater suction powerand thus a greater flow would be produced in the transfer line, whichcould suck in more solid particles into the transfer line. Thus thevalve should be closed at least below a specific pressure in the workingchamber.

Preferably, the ventilation only takes place in the time periods betweenthe suction phase and the compression phase, where there is asubstantially small flow or no flow at all of the fluid to be deliveredinto the transfer line. As a result, the flow of solid particles intothe transfer line may be prevented.

According to an embodiment of the invention which may be additionallyconfigured with the above-mentioned features of the cited embodiments ofthe invention, a pump device is provided with a pulsator as a driveelement for a main pump head which is located in a delivery line and theworking chamber thereof is provided with a suction-side non-return valveand a pressure-side non-return valve, the working chamber of thepulsator being connected, via a transfer line filled with fluid to bedelivered, to the working chamber of the main pump head such that thepulsator sucks fluid to be delivered in an oscillating manner from thedelivery line into the working chamber of the main pump head or forcessaid fluid to be delivered out of the working chamber, the pump devicehaving a refill reservoir for refilling fluid to be delivered, which isacted upon by a pressure which substantially corresponds to the systempressure.

According to the invention, in all embodiments of the invention thetransfer line may be provided with a cooling system.

According to the invention, in all embodiments of the invention thepulsator may be arranged above the main pump head. Additionally oralternatively, according to the invention the transfer line may beoriented to fall from the pulsator toward the main pump head. Suchembodiments of the invention have the advantage that gravityadditionally counteracts contamination by solid particles through thetransfer line into the pulsator.

According to the invention, the transfer line may be provided with asink as a receiving chamber for solid particles in the fluid to bedelivered.

According to the invention, the working chamber of the pulsator may beat least occasionally acted upon by a compensating medium forcompensating for leakage losses.

According to an embodiment of the invention, which may be additionallyconfigured with the above-mentioned features of the cited embodiments ofthe invention, a pump device is provided with a pulsator as a driveelement for a main pump head which is located in a delivery line and theworking chamber thereof is provided with a suction-side non-return valveand a pressure-side non-return valve, the working chamber of thepulsator being connected, via a transfer line filled with fluid to bedelivered, to the working chamber of the main pump head such that thepulsator sucks fluid to be delivered in an oscillating manner from thedelivery line into the working chamber of the main pump head or forcessaid fluid to be delivered out of the working chamber, the transfer linein at least one portion being subdivided into at least two parallelsubsections.

According to the invention, the transfer line may also be divided upover its entire path, i.e. for example two or more parallel transferlines may be provided.

These embodiments of the invention have the advantage that by providinga corresponding control, for example, the at least two subsections areopened in the suction phase and in the compression phases at least onesubsection (where there are two subsections, preferably alternately oneand then the other subsection) is closed at least partially andpreferably completely, at least during part of the compression phase, inorder to prevent deposits of solid particles in the subsections by theresulting higher outflow velocity in the other subsection(s).

According to the invention, the volume of the subsections of thetransfer line extending parallel and/or the volume of the transfer linesextending parallel may respectively be at least as great as, orpreferably greater than, the swept volume of the pulsator.

This development of the invention has the advantage that an escape ofsolid particles into the remaining transfer line and/or the pulsator mayin all likelihood be prevented.

According to the invention, control valves may be provided for at leastpartially opening and closing the subsections of the transfer lineand/or the parallel transfer lines.

According to the invention, a sensor system may be provided in order tosynchronize the timed control of the control valves with the respectivephase position of the pulsator diaphragm. For example, a sensor and/orswitch may be provided which operates the control valve in at least oneend position of the diaphragm of the pulsator. Alternatively oradditionally, a sensor and/or switch may be provided for the otherdiaphragm position, in order to operate the control valve.Alternatively, the control valves could also only be displaced into aclosed position and/or partially closed position during one part of thecompression phase. It might also be conceivable during a compressionphase to close, at least partially, different control valves insuccession.

According to the invention, in the region in front of the main pumphead, the transfer line may preferably be subdivided into a plurality oflines arranged parallel, preferably two lines arranged parallel, whichat least partially and preferably completely may be able to be at leastpartially closed by a time-controlled and/or pressure-controlled valve.

The time control and/or pressure control should be adjusted so thatduring the suction phase all lines are open as long as possible, so thatthe flow is distributed to the different parallel lines, whilst in thecompression phases a portion of the line is alternately subjected to thefull pressure and thus a substantially greater flow velocity. As aresult, contamination of solid particles in the transfer line should bereliably avoided.

According to an embodiment of the invention which may be configured withthe aforementioned features of the cited embodiments of the invention, apump device is provided with a pulsator as a drive element for a mainpump head which is located in a delivery line and the working chamberthereof is provided with a suction-side non-return valve and apressure-side non-return valve, the working chamber of the pulsatorbeing connected, via a transfer line filled with fluid to be delivered,to the working chamber of the main pump head such that the pulsatorsucks fluid to be delivered in an oscillating manner from the deliveryline into the working chamber of the main pump head or forces said fluidto be delivered out of the working chamber, the main pump head having atleast two suction-side non-return valves arranged in parallel (16, 161).

This embodiment of the invention has the advantage that during thecompression phase in the portion of the line between the outlets of thetwo suction-side non-return valves, a greater flow velocity is producedso that the risk of the entry of solid particles into the transfer linefrom the suction-side non-return valve which is downstream relative tothe flow direction is reduced during the compression phase.

According to the invention, the cross section of the line receiving thesuction-side non-return valve which is downstream relative to thedirection of flow during the compression phase, is greater than thecross section of the line receiving the other suction-side non-returnvalve.

This is the preferred execution of this embodiment according to theinvention, as then more solid particles are conveyed by the line, whichprovides increased safety relative to the contamination of solidparticles in the transfer line. Alternatively, the cross sections of thetwo lines could also be the same size or more than two lines and acorresponding number of suction-side non-return valves could beprovided. Also conceivable is a larger cross section of the suction-sidenon-return valve which is upstream relative to the flow direction duringthe compression phase, which still provides an advantage, albeit small,relative to the embodiments with only one suction-side non-return valve.

According to an embodiment of the invention which may additionally beconfigured with the above-mentioned features of the cited embodiments ofthe invention, a pump device is provided with a pulsator as a driveelement for a main pump head which is located in a delivery line and theworking chamber thereof is provided with a suction-side non-return valveand a pressure-side non-return valve, the working chamber of thepulsator being connected, via a transfer line filled with fluid to bedelivered, to the working chamber of the main pump head such that thepulsator sucks fluid to be delivered in an oscillating manner from thedelivery line into the working chamber of the main pump head or forcessaid fluid to be delivered out of the working chamber, a separatingpiston being arranged in the transfer line.

These embodiments of the invention have the advantage that theseparating piston prevents solid particles thereon from passing throughthe transfer line from the main pump head to the pulsator.

According to the invention, the aforementioned embodiments of the pumpdevice according to the invention may be configured with a dual-actingpulsator and two pump circuits controlled in opposing directions.

According to an embodiment of the invention, which may be additionallyconfigured with the aforementioned features of the cited embodiments ofthe invention, a pump device is provided with a pulsator as a driveelement for a main pump head which is located in a delivery line and theworking chamber thereof is provided with a suction-side non-return valveand a pressure-side non-return valve, the working chamber of thepulsator being connected, via a transfer line filled with fluid to bedelivered, to the working chamber of the main pump head such that thepulsator sucks fluid to be delivered in an oscillating manner from thedelivery line into the working chamber of the main pump head or forcessaid fluid to be delivered out of the working chamber, the pulsatorbeing configured as a dual-acting pulsator, one side thereof beingconfigured as a drive element for the main pump head and the other sidethereof being acted upon by a pressure which substantially correspondsto the system pressure.

Such embodiments of the invention with a dual-acting pulsator fordriving two mutually controlled pump circuits are preferred as,consequently, uniform delivery may be achieved. Furthermore, thepulsator at high suction pressures of, for example, 250 bar may bedriven by a drive designed for substantially lower pressures, if forexample a dual-acting piston is used, which only has to overcome thepressure difference between the pressure during the compression phase inthe one pulsator half and the pressure during the suction phase in therespective other pulsator half. This advantage also applies todual-acting pulsators for driving only one pump circuit, if the otherside of the pulsator which does not drive the pump circuit is acted uponby pressure. Advantageously, in embodiments of the invention with arefill reservoir for the diaphragm control chamber(s) of the pulsator,the refill reservoir is acted upon by a pressure which correspondsapproximately to the system pressure, so that also during the refillprocess, which takes place in a valve-controlled manner, if thediaphragm reaches its rear mechanical abutment, the drive is notsubjected to a greater pressure than the difference in pressure betweenthe suction phase and compression phase, and thus does not have to be oflarger size, and the diaphragm is also not destroyed on the flowchannels of its rear mechanical abutment.

According to the invention, a diaphragm position-controlled refilldevice and/or ventilation device for hydraulic fluid may be provided inthe pulsator as, for example, is disclosed in EP 0 085 725 A1.

According to the invention, for compensating for leakage losses in thediaphragm control chamber compensating medium may be present in a refillreservoir that is connected to the diaphragm control chamber via avalve, the refill reservoir being acted upon by a pressure which isgreater than atmospheric pressure.

This embodiment of the invention has the advantage that the pulsator maybe driven by a drive (for example hydraulically, mechanically and/orpneumatically, for example a piston drive), the power thereof onlyhaving to overcome the pressure difference between the suction side andthe pressure side. Moreover, by pressure acting on the refill reservoirfor compensating for leakage losses in the diaphragm control chamber, animpact on the drive, for example the piston, may be prevented.Advantageously, said pressure in the refill reservoir may correspondapproximately to the system pressure. According to a furtheradvantageous embodiment of the invention, a pressure control adapted tothe system pressure by means of a control circuit may be provided in therefill reservoir, as is disclosed, for example, in EP 1 898 093 A1.

According to the invention, the pulsator may be designed to have adiaphragm or tubular diaphragm.

According to the invention, the pulsator may be designed to have apiston or plunger.

A basic idea of the invention, therefore, is also that the pulsator actsupon a main pump head, which in principle is configured as a piston pumphead but without a piston being required. In this manner, a standardcomponent which is suitable for high temperatures and pressures may beused as a pump head which, by combining with a standard diaphragmpulsator, as a whole represents a cost-effective alternative to theknown solutions, the principle of a “remote head” pump being maintained.Wear is also reduced as particles possibly present in the fluid to bedelivered do not come into contact with the working chamber of thepulsator, as the fluid in the transfer line is only moved to and frowithin the range of the pump stroke, and is mixed only slightly withfreshly suctioned fluid. The pulsator may be designed to have adiaphragm or tubular diaphragm and to have a piston or plunger. When thepulsator is a diaphragm pulsator, particles do not enter the diaphragm.As high temperatures in the fluid to be delivered are also reduced overthe course of the transfer line, diaphragm pulsators with cost-effectiveplastics diaphragms, for example made of PTFE, may also be used at highpressures and high temperatures in the delivery line. Thus the pumpdevices according to the invention are particularly well suited fordelivering biomass during the production of biofuel.

A further advantage is that, due to the ventilation, gases from thefluid to be delivered or air inlets may not collect in the pump chamberof the pulsator but are returned to the process. Preferably, to thisend, the inlet in the suction-side delivery line is located above theventing valve so that the gases automatically escape from the workingchamber. Alternatively, there may be forced ventilation, for examplewith a time-controlled and/or pressure-controlled valve.

In order to relieve the diaphragm pulsator still further in terms oftemperature, a preferred development of the invention is that thetransfer line is provided with a cooling system.

It also proves advantageous that the transfer line is orientated to fallfrom the diaphragm pulsator to the main pump head. The particles thusremain in the region of the main pump head and are passed back into thedelivery line.

Alternatively, it may be advantageous that the transfer line is providedwith a sink as a receiving chamber for solid particles in the fluid tobe delivered. Thus in the transfer line a region is provided which islocated below the working chamber of the diaphragm pulsator, so that theparticles collect there due to gravity and do not enter the workingchamber of the pulsator.

It is expedient if the working chamber of the pulsator is acted upon bya compensating medium for compensating for leakages, so that athrough-flow of the transfer line and a migration of solid particles tothe pulsator are prevented.

In order to protect the pulsator even further against solid particlesfrom the fluid to be delivered, a further advantageous embodiment of theinvention is to arrange a separating piston in the transfer line. As aresult of this measure, the part of the transfer line associated withthe pulsator is separated from the part which is associated with themain pump head.

A low driving power is achieved by a dual-acting pulsator and two pumpcircuits controlled in opposing directions being present, which isadvantageous particularly with the use of recirculation processes athigh suction pressures.

The invention is described in more detail hereinafter with reference toexemplary embodiments. In the drawings, schematically:

FIG. 1 shows a vertical section through a first embodiment of a pumpdevice;

FIG. 1A shows a vertical section corresponding to FIG. 1 through afurther pump device according to the invention, comprising a dual-actingpulsator and two pump circuits controlled in opposing directions.

FIG. 2 shows a circuit diagram of a pump configuration made up of twopump devices according to FIG. 1 according to the invention;

FIG. 3 shows features of further embodiments of a pump device accordingto the invention.

FIG. 4 shows a circuit diagram corresponding to FIG. 2 of an alternativepump configuration according to the invention;

FIG. 5 shows a circuit diagram corresponding to FIG. 2 of a furtheralternative pump configuration according to the invention;

FIG. 6 shows a circuit diagram corresponding to FIG. 2 of a furtheralternative pump configuration according to the invention;

FIG. 7 shows a circuit diagram corresponding to FIG. 2 of a furtheralternative pump configuration according to the invention;

FIG. 8 shows features of further embodiments of a pump device accordingto the invention.

FIG. 9 shows features of further embodiments of a pump device accordingto the invention.

FIG. 10 shows a circuit diagram of a pump configuration made up of twopump devices according to FIG. 1 according to the invention;

FIG. 11 shows a P-V-diagram of the time curve of the pressure of thepump over the swept volume with an indication of possible refillingduring the compression phase.

FIG. 12 shows a P-V-diagram of the time curve of the pressure of thepump over the swept volume with an indication of possible refillingduring the suction phase.

In the description of the exemplary embodiments, the following referencenumerals are used:

-   -   1 Pump device    -   4 Connection (for a refill reservoir)    -   5 Pressure side (of the delivery line)    -   6 Delivery direction    -   7 Connection (for the transfer line)    -   8 Connection (for ventilation)    -   9 Venting valve    -   10 Diaphragm pulsator    -   11 Main pump head    -   12 Transfer line    -   12′ Transfer line    -   121 Subsection of the transfer line    -   122 Subsection of the transfer line (arranged in parallel with        the subsection 121 of the transfer line)    -   123 Control valve (preferably a pressure-controlled or        time-controlled shut-off valve)    -   124 Control valve (preferably a pressure-controlled or        time-controlled shut-off valve)    -   13 Inlet    -   14 Outlet    -   15 Suction side (of the delivery line)    -   16 Suction-side non-return valve    -   161 Suction-side non-return valve (arranged in parallel with the        suction-side non-return valve 16)    -   17 Pressure-side non-return valve    -   18 Working chamber (of the main pump head)    -   20 Working chamber (of the diaphragm pulsator)    -   21 Delivery fluid    -   22 Control inlet (of the main pump head)    -   23 Cooling jacket    -   24 Solid particles    -   25 Portion (in the transfer line)    -   26 Diaphragm    -   27 Diaphragm control chamber    -   28 Piston    -   281 Disk    -   29 Motor    -   30 Refill reservoir    -   31 Valve    -   32 Separating piston    -   33 Region (on side of main pump head)    -   34 Region (on side of diaphragm pulsator)    -   35 Displacement direction of separating piston    -   36 Collection container    -   37 Refill valve of diaphragm control chamber    -   38 Hydraulic pump    -   39 Venting valve of diaphragm control chamber

According to FIG. 1 a pump device 1 has a diaphragm pulsator 10 servingas a pulsator, a main pump head 11 and a transfer line 12. The main pumphead 11 has an inlet 13 and an outlet 14 for installation in a deliveryline, the pressure side thereof being denoted by 5 and the suction sidethereof by 15. A suction-side non-return valve 16 is present on theinlet side (suction side) and a pressure-side non-return valve 17 ispresent on the outlet side (pressure side). The direction of delivery isidentified by the arrow 6.

Structurally, the main pump head 11 corresponds namely to a pump head ofa piston pump. However, it does not have a piston. Its working chamber18 is instead directly connected to a working chamber 20 of thediaphragm pulsator 10 via the transfer line 12. The diaphragm pulsator10 is provided with a connection 7 for the transfer line 12. Moreover, aconnection 8 is present for ventilation by a venting valve 9 (FIG. 2)and a connection 4 for a refill reservoir 30 (FIG. 2). Thus theoscillating stroke of the diaphragm pulsator 10 causes the delivery inthe main pump head 11 via the fluid column in the transfer line 12.

The transfer line 12 is filled with delivery fluid 21. It passes via acontrol inlet 22 of the main pump head 11 to the working chamber 20 ofthe diaphragm pulsator 10. The transfer line 12 is provided with acooling system, which is formed by a cooling jacket 23 acted upon bycoolant. In this manner, there may be a temperature reduction from, forexample, approximately 360° C. at the main pump head 11, as it typicallyhas the biomass to be delivered in biofuel production, to approximately100° C. on the diaphragm pulsator 10.

As the transfer line 12 contains the delivery fluid 21, which may alsocomprise solid particles 24, a portion is present 25 in the transferline 12 which falls from the diaphragm pulsator 10 to the main pump head11, and which directly discharges into the working chamber 18 of themain pump head 11. At its lowest point, the transfer line 12 is thuslocated at the level of the working chamber 18 of the main pump head 11.The solid particles 24 remain, as a result, due to gravity in theworking chamber 18 of the main pump head 11 and do not enter the workingchamber 20 of the diaphragm pulsator 10. They are instead supplied tothe pressure-side delivery line 5.

The diaphragm pulsator 10 has a diaphragm 26 which is hydraulicallycontrolled via a diaphragm control chamber 27. As a diaphragm material,preferably PTFE is suitable. Alternatively, elastomers, metallicmaterials or composite materials may also be used. The diaphragm controlchamber 27 is acted upon by a piston 28, which is driven mechanically,for example by a motor 29 (FIG. 2) and/or hydraulically and/orpneumatically, for example, by alternately subjecting the chambersadjacent to the disk 281 to pressure. For compensating for leakages, arefill reservoir 30 is present, filled with a compensation medium which,via a controlled valve 31 (FIG. 2), discharges compensation medium intothe working chamber 20 of the diaphragm pulsator 10. The supply isdenoted in FIG. 2 by 4.

With reference to FIG. 1 and FIG. 2, the function of the pump device isdescribed hereinafter. The configuration shown in FIG. 2 has adual-acting pulsator with two pump devices, as illustrated in FIG. 1.The pump devices are arranged in parallel in two branches A, Bcontrolled in opposing directions. Initially, a pump process isdescribed with reference to one branch. In an initial state, the piston28 is moved into the diaphragm control chamber 27 and the diaphragm 26bulges out into the working chamber 20 of the diaphragm pulsator 10. Thetransfer line 12 and the working chamber 18 of the main pump head 11 arecompletely filled with delivery fluid. The suction-side non-return valve16 and the pressure-side non-return valve 17 are closed.

If the piston 28 is extended, this causes a flattening of the diaphragm26 and a negative pressure in the working chamber 20 of the diaphragmpulsator 10. The negative pressure acts via the transfer line 12 in theworking chamber 18 of the main pump head 11, so that the suction-sidenon-return valve 16 opens and delivery fluid 21 is sucked in from thesuction side 15 of the delivery line. With the subsequent opposingstroke of the piston 28, with the bulging of the diaphragm 26, pressureis produced in the working chamber 20 of the diaphragm pulsator 10 whichacts via the transfer line 12 on the working chamber 18 of the main pumphead 11. The pressure causes a closing of the suction-side non-returnvalve 16 and an opening of the pressure-side non-return valve 17, sothat delivery fluid 21 is pumped into the pressure side 5 of thedelivery line. By the oscillating movement of the piston 28 a continuousdelivery takes place in this manner.

By the control of two main pump heads 11 in opposing directions, bymeans of the dual-acting pulsator 10, which is preferably designed inthe manner of a diaphragm, the pumping and suction processes with thetwo circuits A and B are superimposed so that, in particular, withrecirculation processes at a high system pressure and a relatively smalldifference in pressure between the suction line and pressure line only asmall amount of power is required for the drive. Alternatively, eachmain pump head 11 may be controlled by a single-acting pulsator in thesame or opposing direction.

In FIG. 3, a portion of a transfer line 12′ is illustrated as a detailof a second exemplary embodiment. For separating the fluid column in thetransfer line 12′ a separating piston 32 mounted longitudinallydisplaceably along the double arrow 35 is arranged in the transfer line12′. Solid particles 24, which are possibly present, thus remain in aregion 33 on the main pump head 11 side and may not enter a region 34 onthe diaphragm pulsator side.

FIG. 1A shows an embodiment with a dual-acting pulsator. FIG. 1Asubstantially corresponds to the embodiment shown in FIG. 1, inprinciple the pump device of FIG. 1 being present twice, and beingdriven by a common piston 28. The dual-acting pulsator is shown inextremely simplified fashion in FIG. 1A, i.e. without a drive andwithout a hydraulic reservoir, and the refill valves are acted upon bypressure. The dual-acting piston 28 describes an end position (to theright the diaphragm 26 bulges out, i.e. the compression stroke and/orthe compression phase is complete; to the left the diaphragm 26 isflattened, i.e. the suction stroke and/or the suction phase iscomplete).

The embodiments shown in FIGS. 2, 4, 5 and 6 of the inventionsubstantially differ only by the different ventilation and/or refilling.The same components and features are described using the same referencenumerals. Regarding the exemplary embodiments of FIGS. 4, 5 and 6,therefore, reference is made to the above description of the exemplaryembodiment of FIG. 2, and hereinafter only the differences from thisembodiment of the invention are described.

FIG. 2 shows an embodiment with ventilation into the suction line 15.The refilling takes place from a pressure store 30 (with a gas cushion)in a time-controlled and/or pressure-controlled manner during thecompression stroke of the pulsator. The graphic symbol used for thevalve 31 describes a controlled non-return valve, of which the closingis prevented when activated. The pressure in the refill reservoir 30 hasto be greater than the system pressure. The refill volumetric flow hasto be greater than/the same as the leakage flow of the ventilationprocess. A subsequent adjustment of the storage pressure is recommendeddepending on the changing system pressure. If required, manual controlis also possible.

FIG. 4 shows an embodiment with ventilation in the pressure line 5. Therefilling takes place from a pressure store 30 (with a gas cushion) in atime-controlled and pressure-controlled manner during the suction strokeof the pulsator. The graphic symbol used for the valve 31 describes acontrolled non-return valve, of which the opening is prevented whenactivated. The pressure in the refill store 30 has to be greater thanthe suction pressure. The refill volume flow has to be greater than/thesame as the leakage flow of the ventilation process. A subsequentadjustment of the storage pressure is recommended depending on thechanging suction pressure. If required, manual control is also possible.

FIG. 5 shows an embodiment with ventilation into the refill reservoir30. The refilling takes place from a pressure store 30 (with a gascushion) in a time-dependent manner. The symbol for the refill valve 31shows no specific function.

FIG. 6 shows an embodiment with ventilation into any storage orcollection container 36. The refilling takes place from a pressure store30 (with a gas cushion) in a time-dependent manner. The symbol for therefill valve 31 shows no specific function.

FIG. 7 shows an embodiment of the invention of a pump device with asingle-acting pulsator. The ventilation and/or refilling may take placeaccording to the above-mentioned embodiments of the invention, forexample, according to FIG. 2, FIG. 4, FIG. 5 or FIG. 6. By way ofexample, the ventilation into the pressure line 5 is shown as one of thepossible variants.

In the embodiment of FIG. 7, instead of the single-acting pulsator, adual-acting pulsator could also be used, the side thereof which is notused being acted upon by a pressure which corresponds approximately tothe system pressure, for example by means of a pressure store. Thus theadvantages of a refill medium acted upon by pressure may be utilized forrefilling into the diaphragm control chamber. Moreover, the advantage ofsubjecting the unused side of the dual-acting pulsator to pressure isthat a drive of smaller dimensions may be used, if high pressures of,for example, 250 bar from the pump head driven by the pulsator have tobe overcome.

FIG. 8 shows a possible configuration of the main pump head 11 of pumpdevices according to the invention. On the suction side of the main pumphead two suction-side non-return valves 16, 161 are provided which mayalso have different sizes. This embodiment has the advantage that duringthe compression stroke of the pulsator a greater flow velocity isproduced in the line portion between the two suction-side non-returnvalves.

The transfer line 12 has a gradient toward the suction-side non-returnvalves 161, 16. During suctioning, the suction flow corresponding to thecross-sectional ratios is divided up between the suction-side non-returnvalves 161 and 16. As a result, during suctioning it is achieved that inthe portion of the transfer line between said two suction-sidenon-return valves there is a smaller flow than might be the case if theentire suctioned quantity were to be suctioned only through thesuction-side non-return valve 16.

During the compression stroke, the entire quantity of fluid delivered bythe pump flows through the transfer line. This has the result that fluidflows through the transfer line which, as a whole, is oriented moretoward the suction-side non-return valve 16.

This flow could ensure that the deposits are instead repeatedlydelivered back by the main flow.

FIG. 9 shows a possible configuration of the transfer line 12 of pumpdevices according to the invention. The transfer line is subdivided inat least one portion into at least 2 subsections 121, 122, which aresimultaneously used for suctioning by means of controlled shut-offvalves 123, 124 in the suction phases, and alternately respectivelyopened and closed in the compression phases in order to prevent depositsin the subsections 121, 122 of solid particles thus produced by thehigher outflow velocity.

The filling volume of each of the subsections 121, 122 should preferablybe at least as great as, and preferably greater than, the swept volumeof the pulsator. As a result, solid particles are prevented fromentering behind the controlling valves, by alternately closing in thecompression phase.

In a first suction process, therefore, each subsection would initiallybe filled with particles to a maximum extent of up to half of itsvolume. The subsequently closed subsection would possibly maintain thisstate. With a further suction process, the subsection would then becompletely filled with particles to a maximum extent, before thoroughrinsing would take place in the compression phase.

In the embodiment shown in FIG. 9, time-controlled shut-off valves 123,124 are provided which should be synchronized by means of sensor systemsexactly with the respective phase position of the pulsator diaphragm.

FIG. 10 shows a further embodiment of the invention. The same parts areprovided with the same reference numerals. Reference is made to thedescription of the above-mentioned embodiments. In FIG. 10, the pulsatoris shown in slightly more detail, the drive not being shown for thedual-acting piston 28. The path of the hydraulic channels of thedual-acting pulsator is shown, in particular, in more detail.

The pump device of FIG. 10 has two refill valves 37 of the diaphragmcontrol chamber which preferably are acted upon by a pressure whichcorresponds approximately to the system pressure. The pressure isprovided by a hydraulic pump 38. Moreover, two venting valves 39 areprovided for ventilating the diaphragm control chambers.

FIGS. 11 and 12 show schematic PV-diagrams which show the time curve ofthe pump pressure over the swept volume. Starting at the point on theleft side below, seen very clearly here are the steep flank of the risein pressure during the compression phase, the pressure fluctuations dueto the valve kinematics, the extension of the swept volume (highestpressure at maximum piston velocity) and also the sharp decompressionphase and suction phase. (Note: in the present case, in both figures forreasons of clarity the cycle has been shown clockwise).

The dotted line in FIG. 11 shows the required pressure level and apossible time window for a controlled leakage refilling process duringthe compression stroke. The average working pressure of the pulsator setin the compression stroke (pD) is slightly greater than the systempressure.

The dotted line in FIG. 12 shows the required pressure level and apossible time window for a controlled leakage refilling process duringthe suction stroke. During refilling during the suction stroke, it issufficient if the pressure level is slightly above the suction pressure.

1. A pump device comprising a pulsator as a drive element for a mainpump head which is located in a delivery line, the working chamberthereof including a suction-side non-return valve and a pressure-sidenon-return valve, the working chamber of the pulsator being connected,via a transfer line filled with fluid to be delivered, to the workingchamber of the main pump head such that the pulsator one of sucks fluidto be delivered in an oscillating manner from the delivery line into theworking chamber of the main pump head and forces said fluid to bedelivered out of the working chamber, a venting valve being provided forventilating the working chamber of the pulsator, wherein the ventingvalve is one of a time-controlled valve and a pressure-controlleddouble-seat valve, and wherein a device is provided for introducing afluid into the working chamber of at least one of the pulsator and thetransfer line.
 2. The pump device as claimed in claim 1, wherein theworking chamber of the pulsator is connected via a further venting valveto the suction side of the delivery line.
 3. The pump device as claimedin claim 1, wherein the working chamber of the pulsator is connected viaa further venting valve to the pressure side of the delivery line. 4.The pump device as claimed in claim 1, wherein the working chamber ofthe pulsator is connected via a further venting valve to a refillreservoir for compensating for leakage losses in the working chamber ofat least one of the pulsator and the transfer line.
 5. The pump deviceas claimed in claim 1, wherein the working chamber of the pulsator isconnected via a further venting valve to a collection container forcollecting and subsequently returning fluid to be delivered producedduring ventilation.
 6. The pump device as claimed in claim 1, whereinthe pump device has a refill reservoir for refilling fluid to bedelivered, which is acted upon by a pressure which substantiallycorresponds to the system pressure.
 7. The pump device as claimed inclaim 1, wherein the transfer line is provided with a cooling system. 8.The pump device as claimed in claim 1, wherein the pulsator is arrangedabove the main pump head.
 9. The pump device as claimed in claim 1,wherein the transfer line in at least one portion is subdivided into atleast two parallel subsections.
 10. The pump device as claimed in claim9, wherein the volume of the subsections of the transfer line extendingparallel and/or the volume of the transfer lines extending parallel isrespectively at least as great as the swept volume of the pulsator. 11.The pump device as claimed in claim 9, further comprising control valvesare provided for at least partially opening and closing the subsectionsof the transfer line or the parallel transfer lines.
 12. The pump deviceas claimed in claim 1, wherein the main pump head has at least twosuction-side non-return valves arranged in parallel.
 13. The pump deviceas claimed in claim 12, wherein the cross section of the line receivingthe suction-side non-return valve which is downstream relative to thedirection of flow during the compression phase, is greater than thecross section of the line receiving the other suction-side non-returnvalve.
 14. The pump device as claimed in claim 1, further comprising aseparating piston arranged in the transfer line.
 15. The pump device asclaimed in one of the preceding claim 1, wherein the pulsator is adual-acting pulsator, the device further comprising two pump circuitscontrolled in opposing directions.
 16. The pump device as claimed inclaim 1, wherein the pulsator is configured as a dual-acting pulsator,one side thereof being configured as a drive element for the main pumphead, and the other side thereof being acted upon by a pressure whichsubstantially corresponds to the system pressure.
 17. The pump device asclaimed in claim 1, wherein the pulsator is designed to have a diaphragmor tubular diaphragm.
 18. The pump device as claimed in claim 1, whereinthe pulsator is designed to have a piston or plunger.